The present invention uses a variable previously not used by petroleum geologists--the response of a reservoir to tidal forces.
The word "tide" generally invokes an image of a changing water level at a shoreline, but the moon and the sun also cause tides in the atmosphere, they cause tides in the solid earth, and they cause changes to reservoirs within the solid earth. The "earth-tide" is associated with a periodic dilation and constriction of the earth's crust caused both by the gravitational attraction of the earth to the moon and the sun (other celestial bodies being too far away to appreciably influence the earth) and by the changing weight loads caused by the water tide and atmospheric tide. The present invention is based in part on the fact that hydrocarbon reservoirs respond to this periodic deformation of the earth and to the forces that cause this periodic deformation.